The distinctive pattern of nerve fibers in the retina of the human eye, particularly the pattern of convergence toward the point of fixation, may provide the basis for a remote optical detector that can sense when an eye is looking at it. Such a "fixation monitor" would not only have medical applications in the fields of strabismus diagnosis, perimetry, and eye movement research, but also could enable handicapped individuals or others to activate external devices, such as keyboards or control panels, simply by looking at them and blinking. Safe levels of infrared light from a GaAlAs IR light-emitting diode (880nm) will be used in continuous mode, and in pulsed mode if necessary. Several optical designs for the fixation monitor will be investigated. Optically scanning the source in a circle may be the simplest way to minimize light exposure while also providing the most useful signal to identify the fovea. If such a fixation monitor can be shown to be feasible, it can subsequently be adapted to wide-ranging applications.